Polystyrene Foam Cladding

Any comments or experiences with polystyrene foam cladding for external walls?

Has been suggested by our builder instead of hebel



  • My only suggestion without knowing much about it would be to check how easily it compresses. Just in case in the future you want to mount something to. Awnings, clothes line etc

  • why?

  • What is the price difference?

    • not exactly sure yet

  • +2

    Does it burn well?

    • only one way to find out!

  • It would be easier and cheaper for him to install. Polystyrene cladding you don't need to build foundations for the external walls.

    Also the builder can use the R rating of the Polystyrene when calculating the amount of insulation he needs to put in the walls to meet the 6 Star energy rating.

    I did 100mmm polystyrene cladding with R2.5 sound deadening batts in the walls. Ended up with R5.0 overall rating which means minimal heat lose through the walls.

    Would recommend 100mm over 75mm for the improved sound and insulation rating. Check the cladding system as most of them require you use their render as a pairing with the poly to meet the local fire ratings. If you live near bush land this is critical.

    Finally poly is now banned from buildings of 3 or more levels. single and double storey is ok.

    • My land slopes significantly and to match the existing house floor the frame/walls of the extension are built on about 6 besser blocks high

  • Are their names Geoff & Terry by any chance?

  • Is he suggesting ground floor? From what I have seen normally only top story is done with foam

    Like everything they are not all the same. They good ones have a hard layer of cement sheet on the outside

    • Yes technically I guess but it's a fair distance off the ground due to the besser blocks, see my comment above

      Will be rendering after so that'll add some hardness yea!

  • Which is less flammable?

  • Person across the street had there top story done by these guys.

    Looks good, can't even tell after it has been rendered.


  • +1

    Have used it in the past for the 1st storey cladding. Good insulation and can't see the difference between hebel/brick.

    BUT I wouldn't use it on the ground floor due to potential damage. Can't mount anything on it and you're bound to damage it with a wheelbarrow or knocking it.

    Go for Hebel.

  • Most new brick builds in the parts of Europe that get cold have foam on the outside, brick on the inside, render in and out (or sometimes plasterboard inside). This is the smart way - you want thermal mass inside, insulation outside. Our brick-veneer builds are essentially opposite that but we're lucky to not get that cold in most places, but we do suffer the heat in summer. Australia is years behind in building tech.

    • Interesting thanks!

  • It’s not durable at low level, so you want to be mindful of that, but Hebel is also susceptible on corners, but this stuff would be next level in terms of its lack of durability. I’ve only ever seen it being used on upper storeys.

    If you were ever unfortunate enough to have your house catch fire, this stuff would be a pretty horrible situation with dense, toxic smoke. Hebel doesn’t really burn.

    • Would rendering add any significant benefit in terms of durability and preventing damage?

      • Put the durability argument in context. How regularly does your house get hit by a sledgehammer vs how regularly are you paying for heating and cooling?

        The rendering (with a steel or fibreglass net/mesh substrate) does add strength. Houses in Europe seem to do fine.

        A plain rendered Hebel ain't gonna be much better - it chips much easier.

        • Good point!

          • @Heracles26: Also, before it's raised, I am not sure what sort of anchors they use with external foam to affix things like awnings and clotheslines - but it's obviously do-able.

            • @afoveht: Things like garden tools, ladders, wheelbarrows, bike pedals, crazy toddlers might damage it when hit front on. I've got EPS foam insulation on the back of my garage door (not rendered obviously) and I've damaged and dented it plenty of times moving stuff around, it's a pain as I can't repair, but it's only my garage. Think about how hard it is going to repair when it's outside. Patching render is not a 2 minute job you can do yourself. The render is your first line of defence against water protection as well.

              I think the render adds a bit of protection because there is a thin layer of mesh, but I'd speak to Dulux about their experience and how much their products (Acratex etc.) actually add to durability.

              Back to the fire thing, Victoria has banned the product on Type A and Type B construction (which is multi-storey commercial and multi-residential apartments). https://www.vba.vic.gov.au/__data/assets/pdf_file/0011/97580...
              Combustible cladding is the new asbestos in terms of insurance liability. At this stage it's commercial, but it only takes one loss of life insurance claim due to a certain product for it being banned on houses. I would be really hesitant to use it given how risk adverse insurers are getting in this field, and future issues insuring your property.

  • What is the warranty offered from the builder on the foam vs brick or hebel wall

  • Nothing wrong with foam as long as it is rendered properly with enough coates and taped and jointed properly. Should only be used on upper floors not on ground level.

    Hebal panel joins also needs to be jointed properly before rendering as well to ensure the joint not shown through render.



  • We were going to be a double story but our builder only does foam cladding on the top. Do some research. It’s been banned in Europe as there has been a link to causing cancer.

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